1. Field of the Invention
The present invention relates to a refrigerating and humidity-regulating system for a container to be used accommodating Freight in a cold storage or refrigerated condition in marine or overland transportation.
2. Description of the Prior Art
Heretofore, in the case where it is necessary to humidify inside air of the above-mentioned type of container, as shown in FIG. 8, a humidifier 02 is disposed within a refrigerating unit 01, and the inside air within a container 03 is circulated as indicated by arrows.
The inside air is sucked into the refrigerating unit 01 through its top portion and is, after being accelerated by a blower 04, cooled in the course of passing through a cooling coil 05, and is subsequently blown out through the bottom portion of the refrigerating unit 01, after being humidified by the humidifier 02.
As the humidifier 02 can be used an ultrasonic humidifier, a steam type humidifier, a centrifugal humidifier, etc., and water is supplied to the humidifier 02 from a water tank 06 disposed within the container 03.
When this humidifying method is employed, since it is necessary to house the water tank 06 for supplying water to the humidifier 02, not only is the freight loading space within the container 03 reduced, but in the event that the container is transported for a long period of time, it may be necessary to supplement the water in the water tank 06, or there may be an inconvenience in that the water within the water tank 06 may possibly become corrupt.
In the case where it is necessary to dehumidify inside air of the container, as shown in FIG. 9, a dehumidifying coil 07 is disposed within a refrigerating unit 01.
The inside air is, as indicated by arrows, sucked into the refrigerating unit 01 through its top portion and made to pass through the dehumidifying coil 07 via a blower 04 and a cooling coil 05. During this process, moisture in the inside air is removed by making it dew on the surface of the dehumidifying coil 07. The water dewed on the dehumidifying coil 07 is collected in a drain pan 08 and discharged to the outside of the refrigerating unit 01.
When this dehumidifying method is employed, since the dehumidifying coil 07 is cooled to a temperature lower than a dew point of the inside air and moisture in the inside air is removed by making it dew on the surface of the dehumidifying coil 07, there is a limit of dehumidification of up to a relative humidity of RH 50%, hence it is extremely difficult to maintain a humidity lower than that value, and also, within a low temperature atmosphere the moisture adhered to the dehumidifying coil 07 would freeze, resulting in the lowering of heat transfer efficiency and degradation of the dehumidifying effect. In order to deal with this problem, if the dehumidifying coil 07 is heated to melt the ice adhered to the coil, the melted water would give off moisture to the inside air, and would result in an inconvenience in that the dehumidifying effect would be halved.